Thread-safe ARPACK test case failed

[Tamás Nepusz]

Once out of ~100 runs of "make check", the thread-safe ARPACK test case failed once. Log attached.

[Gábor Csárdi (gabor.csardi)]

Is this 64 bit? 32 bit Ubuntu seems to work fine.....

[Tamás Nepusz (ntamas)]

Yup, 64-bit as far as I remember.

[Gábor Csárdi (gabor.csardi)]

Still cannot reproduce it, ubuntu 12.04 64 bit in virtualbox. Run it a thousand times.... I'll run it more, but if you can reproduce it, please can you send the a core dump? Thanks.

[Tamás Nepusz (ntamas)]

Actually, on second thought, it could be related to the fact that I configured igraph to use an external ARPACK implementation and not the built-in one, so no wonder that the test case fails since most (if not all) external ARPACK libraries are not thread-safe... which leads to the conclusion that we should disallow external BLAS, LAPACK or ARPACK implementations if igraph is configured in thread-safe mode.

[Gábor Csárdi (gabor.csardi)]

OK, that makes sense. I can simply change configure.in to forbid using --enable-tls and --with-external-arpack at the same time. Internal ARPACK is the default, and TLS support is autodetected, so the problem only comes up if the user supplies --with-external-arpack. We can then give an error message that --disable-tls is also needed in this case. Is this good?

[Tamás Nepusz (ntamas)]

Sounds good.

[Gábor Csárdi (gabor.csardi)]

Fixed in revision #2736 (0.6-main).

[Gábor Csárdi (gabor.csardi)]

The development of igraph has moved to github, so please do not comment on this bug here. You are of course welcome to comment on github, here:
https://github.com/igraph/igraph/issues/290